Adjustable positionable structural device

ABSTRACT

A structural device composed of lazy-tong frame members is adjusted to different positions by an enclosed piston, which exerts a force upon the structure in a location providing improved stability in the device while the position is being adjusted. Stabilizer arm members situated substantially parallel to the lazy-tong frame members assist in overcoming twisting forces, and consequent lateral movement, created when the position is being adjusted. The lazy-tong frame members and stabilizer arms are mounted at their ends to angle iron corner members which prevent the structure from locking up when such structure is in a collapsed position. Adjustable tension spring loading is provided at the mounting between the lazy-tong frame members and the angle iron corner members, to assist in overcoming and neutralizing inertia and friction in the structure.

United States Patent Fulcher [54] ADJUSTABLE POSITIONABLE STRUCTURALDEVICE [72] Inventor: Junius H. Fulcher, Houston, Tex.

[73] Assignee: Cooper Industries, Inc., Houston,

Tex.

[22] Filed: Jan. 20, 1971 [21] Appl. No.: 108,094

[52] US. Cl. ..52/l09, 182/63, 182/141 [51] Int. Cl ..E04g 1/22 [58]Field of Search ..l82/63,141,148, 69, 157;

[56] References Cited UNITED STATES PATENTS 2,625 ,443 1/1953 Sesenbaugh..182/14l 1,859,830 5/1932 Kummel ..182/141 3,015,497 1/1962 Aldred..182/17 2,798,641 7/1957 Coddington ..182/l41 1,135,440 5/1915 Javal..254/122. 2,767,812 10/1956 Boger ..52/l09 Oct. 31, 1972 990,399 5/1911Smith ..245/277 Primary Examiner-Reinaldo P. Machado Attorney-Owen &Owen [5 7] ABSTRACT A structural device composed of lazy-tong framemembers is adjusted to different positions by an enclosed piston, whichexerts a force upon the structure in a location providing improvedstability in the device while the position is being adjusted. Stabilizerarm members situated substantially parallel to the lazytong framemembers assist in overcoming twisting forces, and consequent lateralmovement, created when the position is being adjusted. The lazy-tongframe members and stabilizer arms are mounted at their ends to angleiron corner members which prevent the structure from locking up whensuch structure is in a collapsed position. Adjustable tension springloading is provided at the mounting between the lazy-tong frame membersand the angle iron corner members, to assist in overcoming andneutralizing inertia and friction in the structure.

3 Claims, 9 Drawing Figures P'A'TENTEDH'BI I 1912 r 3.701.226

SHEET 3 0F 3 PWJ Wm & Mme

ATTORNEYS ADJUSTABLE POSITIONABLE STRUCTURAL DEVICE BACKGROUND OF THEINVENTION DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, theletter D designates generally an The field of this invention isadjustably positionable adjustably positionable structural device ofthis invenstructural devices such as platform lifts, scaffolding,extendible crane booms, structural members and the like.

The prior art, such as US. Pat. No. 3,053,351, taught the use ofstructural devices composed of lazy-tong frame members. However, suchstructural devices if sufficiently large suffered diminished stabilitydue to improper resolution within the device of the forces appliedthereto, causing twisting and lateral movement when the position of thestructural device was being changed. Further, the devices required thatrelatively large forces be applied to adjust the position of suchdevices, in order to overcome the friction in the connections betweenlazy-tong frame members, and the inertia of the structure. When thedevice was initially fully collapsed, it had a tendency to lock-up, dueto the inertia of the device and the friction between frame members atthe connections.

SUMMARY OF THE INVENTION With the present invention, an adjustablypositionable structural device is provided comprising a plurality offrames composed of lazy-tong frame members, connected at their ends toangle iron corner members which prevent the structure from locking upwhen in a collapsed position, and preferably with adjustably tensionedspring clips positioned at the connection between the frame members andthe corner members, to assist in overcoming and neutralizing inertia ofthe device and friction between frame members at the connections. Theforce required to adjust the position of the device is generated by acylinder and piston situated interiorly with respect to the frames, withthe force created by the expanding piston transmitted to cables whichare attached to the frames at suitable positions to apply the forces tothe frames to increase the stability of the device during movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of anadjustably positionable platform according to the present invention, ina raised or elevated position;

FIG. 2 is an elevational view of a platform adjusted to its fullycollapsed position;

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is an isometric view of the moving force generating portion ofthe adjustable structural device of the present invention;

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 3;

FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 4;

FIG. 8 is an enlarged sectional view illustrating in detail the portioncircled in FIG. 1 and having the numeral 8 designating same; and

FIG. 9 is a cross-sectional view taken along the line 9-9 of FIG. 8.

tion. As will be explained in detail, the device D is movable to pluraladjustable positions by application of suitable adjusting forces, and issuitable for use as a platform, scaffolding, elevator, extendible craneboom, structural member or the like.

In FIG. 1, the device D used as a movable platform is shown, comprisinga platform T with an associated guard rail G, positioned atop aplurality of frames F, each comprising plural lazy-tong frame members 20pivotally connected at their ends 21 and 22 to a corner member 30, andpositioned atop a base member B.

The platform T comprises a work surface 10, upon which a worker or riderand cargo can be positioned, a cruciform support member 11, and aplurality of tracks 12, each mounted to the support member 1 1.

Each of the lazy-tong frame members 20 is pivotally connected at itscenter to a corresponding lazy-tong frame member 20a and at its ends 21and 22 to corner members 30, in a manner to be later discussed. Thelazy-tong frame members 20 and 20a may be of several configurations,such as angle iron members, rods, or flat bars, or any of the variousconfigurations disclosed and discussed in US. Pat. No. 3,053,351. Aplurality of stabilizer bars 25 are positioned substantially parallel toselected ones of the lazy-tong frame members 20, such stabilizer bars 25being pivotally connected at their centers to a corresponding stabilizerbar 25a, and at their ends to corner members 30 to enhance the stabilityof the device D in a manner to be later discussed.

A plurality of clevis-shaped members 33 are mounted with respect to aplurality of corner members 31 atop each of the frames F, and a likeplurality of clevis-shaped members 34 are mounted with respect to aplurality of corner members 32 at the base of each of the frames F.

The clevis-shaped members 34 each enclose an arm 41 of a cruciformsupport member 44 of base B. An outrigger, or support leg, 42 ishingably mounted with respect to each arm 41 of the support member, andhas a base pad 43 hingably mounted with respect to such leg. The pad 43engages the surface upon which the device D is to be positioned foroperation, and provides a broad support base as will later be discussedfor the frame member F. A dolly 50 with attached wheels 51 alsocomprises a part of the base member B, and facilitates movement of thedevice D from one location to another.

A cylinder with an associated piston P, to which a bridle 60 is mounted,is situated interiorly with respect to the frame members F, and createsthe movement required to adjust the position of the device D in a mannerto be described.

A plurality of pulleys 61, each of which is mounted with respect to anarm 65 of the bridle 60, and over which a cable or rope 62, affixed atone end to eyelets formed in a plurality of flanges 63 extending fromthe arms 41, and at the other end to one of the intermediate cornermembers 30, impart the motion of the piston P with respect to thecylinder C to the frame members F.

In FIG. 2, the device D is shown in a collapsed position, with likeparts bearing like reference numerals to FIG. 1. To preserve clarity inthe drawings, several reference numerals have been omitted from FIG. 2.The piston P is substantially completely enclosed within the cylinder C,and each of the frame members F is substantially fully collapsed withthe pivotally connected lazy-tong frame members and 20a being spacedtheir maximum angular displacement with respect to each other abouttheir pivot center connection. When the device D is in the collapsedposition, each of the corner members is in contact at an upper surface30a and a lower surface 30b with the lower surface and upper surface,respectively, of the adjacent corner members, stacking to form a solidcolumn of such corner members and displacing the pivotally connectedends 21 and 22 of the lazy-tong frame members 20 relative to thepivotally connected ends of adjacent frame members. The displacement ofthe pivotally connected ends 21 and 22 prevents adjacent pivotallyconnected ends from coming into engagement with respect to one anotherand due to such engagement causing the device D to lock-up in thecollapsed position, whereby the pivotally connected ends cannot movefreely with respect to one another in response to the movement of thepiston P, and thus are resistant to a change in position of the deviceD.

The cables 62 are connected to a respective intermediate corner member30, intermediate the upper and lower ends of the frame members F so thatthe force created by the motion of the piston P, when applied to thecorner members 30, resolves itself into a vertical component, whichmoves the corner member 30 upwardly when the device D is being movedupward, and correspondingly downward when the device D is being moveddownward, and two rectangular horizontal components which are applied tothe ends of the lazy-tong frame members causing such frame members tomove pivotally with respect to one another as the position of the deviceis being changed. Location of the cable attachment at corner members 30intermediate the ends of the frames F also permits use of a smaller, andconsequently less expensive, cylinder C and allows further collapse ofthe device D to a lower position, permitting access to the platform at alower height, and occupying a smaller space when the device D is movedfrom one position to another as will later be described.

Should the rectangular horizontal force components be unequal, atorsional or twisting force is created, tending to rotate the frames Fand platform P relative to the base B. To assist in overcoming suchtwisting force, the stabilizer bars 25 and 25a are positioned parallelto selected frame members 20 and 20a according to the dimensions, size,and particular use of the structural device D, to gain additionalstructural support against such force.

When the device D is in the collapsed position (FIG. 2), it may be movedfrom one position to another by means of the dolly 50. The wheels 51may, if desired, be positioned on tracks to facilitate such movement.The device D may also be placed in a truck, trailer or the like andmoved from one job site to another. If the device D is used as aplatform, a ladder or steps could be attached to the platform T to allowthe user to mount the platform T more easily.

In FIG. 3, the structure of the base B, whereby a broader and morestable support for the device is provided, is illustrated. The dolly 50itself provides a sufficiently stable when the device D is in thecollapsed position (FIG. 2). However, when the position of the device Dhas been adjusted to a suitable height, a broader and thus more stablebase is desirable.

A plurality of wheels 360 through 36d are positioned withinclevis-shaped members 34a through 34d on axles 38 (FIG. 6), and rideupon an upper surface 50a of the dolly 50 (FIG. 3'). The wheels 36athrough 36d are positioned within grooves in corresponding arms 41athrough 41d of cruciform member 44, and move within such grooves toallow inward and outward movement of the lower corner members 32athrough 32d, and thus the lower ends of the frames F, with respect tothe upper surface 50a and the dolly 50 when the position of the device Dis being adjusted. Flanges 63a through 63d, in which eyelets for thepassage of the cable 62 are formed, are positioned on an upper surfaceof the arms 41a through 41d, respectively, and the cylinder C, withinwhich the piston P is positioned, is positioned at the center of thebase member 44 where the arms 41a through 41d intersect. The supportlegs 42a, 42b, 42c and 42d are hingeably mounted by pins, bolts or othersuitable means, illustrated as 45a and 45b, at the ends of arms 41a,41b, 41c and 41d, respectively outside of the dolly 50. The support pads43a, 43b, 43c and 43d are hingeably mounted by pins, bolts or othersuitable means 46a to the ends of support legs 42a, 42b, 42c and 42d,respectively, opposite the dolly 50. The pads 43 thus engage the surfaceupon which the device D is positioned at a greater distance from thedevice D than the dolly 50, providing a broader support base for thedevice D, thereby rendering the device more stable when such device isat an elevated position (FIG. 1), particularly if the surface upon whichthe device D is positioned is rough or uneven.

In FIG. 4, the pulleys 61 mounted to the arms 65 of 'the bridle 60extending outwardly with respect to a v stem S of the piston P areshown. A plurality of wheels 37a, 37b, 37c and 37d are positioned withinclevisshaped members 33a, 33b, 33c and 33d axles 39 (FIG. 7) and engagethe lower surfaces 13a, 13b, 13c and 13d of the tracks 12a, 12b, 12c and12d (FIG. 4), respectively, moving within such tracks to allow inwardand outward movement of the upper corner members 31a through 31d, andthus the upper ends of the frames F with respect to the tracks 12 andthe platform P, when the position of the device D is being adjusted.

In FIG. 5, the means for generating the forces required to adjust theposition of the device D is shown, comprising a cylinder C mounted withrespect to the arms 41 of the base member 44, containing a piston Pwhose stem S has attached at an end opposite the cylinder C a bridle 60comprising a plurality of outwardly extending flanges 65a through 65a'to which are mounted pulleys 61a through 61d, respectively. A pluralityof cables 62a through 62d are respectively attached to eyelets in theflanges 63a through 63d in the arms 41a through 41d of the base member44, and to intermediate corner members 30.

The piston P may be pneumatically, hydraulically, electrically ormechanically moved from one position to another to adjust the positionof the structural device. If pneumatic or hydraulic means are used, a

check valve and line bleeder may be included for safety purposes.

Movement of the piston P caused by suitable means set forth above causesthe stem S and bridle 60 to-correspondingly move, exerting by means ofpulleys 61a through 61d, and cables 62a through 62d, respectively,corresponding forces on the intermediately located corner members 30 ofthe frames F, thereby adjusting the position of the device D to thedesired position.

In FIG. 8 and FIG. 9, the mounting of lazy-tong frame members and 20awith respect to the corner member 30 is illustrated. An opening 28 isformed in the ends 21 (not shown) and 22 of each of the frame members 20and 20a, and a similar opening 30c (in each wall of the angle ironcorner member 30) is formed by drilling or other suitable techniques.Another opening 29 is also formed in the ends 21 and 22, and acorresponding pair of openings 30d and 30e are formed in the angle ironcorner member 30. A suitable attaching device 80 which could be forexample a bolt, pin, brad, cotter key or the like is inserted throughthe openings 28, 30c and 28a to attach the frame members 20 and 20a tothe corner member 30. A spring 70 is then tensioned and inserted withone end in the opening 29 and the other end in opening 30d, and anotherspring 70a is tensioned and similarly inserted in the openings 29a and302. The force in the tension springs is designed to overcome thefrictional forces between individual frame members, and between framemembers and corner members, as well as the inertia in the device D, allof which tend to resist the forces applied to the device D to adjust itsposition.

The size of the spring 29, and the amount of tension applied, could bevaried in accordance with the position of the corner member to whichsuch spring 29 is mounted. For example, the size and the tension of thespring 29 at the lower corner members 32 should be somewhat larger thanthat of the springs 29 located at the intermediate corner members 30 andat the upper members 31. Also, similar spring tensioning arrangementscould be accomplished with respect to the stabilizer bars 25.

' In the operation of the present invention as an adjustablypositionable platform, the user desiring access to an elevated positionplaces himself and the tools and/or materials he requires on the surface10 of the platform T, and either a co-worker or the user actuates themotor or other suitable device to cause the piston P to move withrespect to the-cylinder C until the platform T is at a suitable height.The frames F supporting the platform T provide support for such platformand make the platform self-supporting and stable even if the user movesabout on the platform. The device D offers a safety feature ofprotection against an overload condition, since if the platform T isoverloaded, the piston P and the cylinder C cannot generate sufficientforce to overcome the overload weight on the platform T, and theplatform T does not move. Another safety feature offered by the deviceis that should the piston P or cylinder C suffer a leak when the deviceD is at an elevated position, the device will not collapse. Rather, thepiston P will slowly be compressed into the cylinder C, due to theweight on the platform T, allowing a slow, gradual safe lowering of suchplatform to the collapsed position (FIG. 2).

Although the device D has been illustrated as comprising four frames Fof lazy-tong frame members, forming a square cross-section, otherconfigurations of frames are equally suitable for use in the device D ofthe present invention, for example a triangular arrangement of threeframes of lazy-tong frame members, or a rectangular arrangement of fourframes.

In addition to serving as an adjustably positionable platform asillustrated in the drawings, the structural device D of the presentinvention is useful as numerous other types of structural devices. Forexample, the device D of the present invention may be used to expandhorizontally and serve as an extendible crane boom, temporary bridge orthe like. The device D with a platform T can also be used as anelevator. A plurality of structural devices D may be situated withboards or runways extending therebetween to serve as highly safe andstable scaffolding. The device D may be used to temporarily replacedamaged utility pole or other structural member while a replacement poleor member is being put into position.

The foregoing disclosure and description of the inventionareillustrative and explanatory thereof, and various changes in thesize, shape, and materials as well as in the details of the illustratedconstruction may be made within departing from the spirit of theinvention.

I claim:

1. An adjustably positionable structural device for use as a platformlift, scaffolding, extendible crane boom, structural member or the like,comprising:

a. a plurality of frames, each of said frames comprising a plurality oflazy-tong frame members, each of said members being pivotally mounted atits center to another frame member and pivotally connected at its endsto other members;

b. force generating means for generating a force to adjust the positionof said frames relative to each other;

0. means for connecting said force generating means to at least oneofsaid frames at a position intermediate the ends thereof; and

d. a plurality of stabilizer bars, each bar being pivotally mounted atits center to another stabilizer bar, and pivotally connected at itsends to other stabilizer bars, and situated substantially parallel to alazy-tong frame member to assist in overcoming torsional forces createdwhen the position of said device is being adjusted.

2. An adjustably positionable structural device for use as a platformlift, scaffolding, extendible crane boom, structural member or the like,comprising:

a. a plurality of frames, each of said frames comprising a plurality oflazy-tong frame members, each of said members being pivotally mounted atits center to another frame member and pivotally connected at its endsto other members;

b. force generating means for generating a force to adjust the positionof said frames relative to each other;

c. means for connecting said force generating means to at least one ofsaid frames at a position intermediate the ends thereof; and

d. said force generating means including:

1. a piston located interiorly of said frames; 2. a bridle mounted withrespect to said piston; 3. a pulley mounted with respect to said bridle;

4. means for adjusting the position of said piston, thereby generatingthe force required to adjust the position of said device; and

5. a cable engaged with said pulley to impart to said frames the forcebeing generated by said piston, said frames being disposed exteriorly ofsaid force generatingmeans.

3. An adjustably positionable structural device for use as a platformlift, scaffolding, extendible crane boom, structural member or the like,comprising:

a. a plurality of frames, each of said frames comprising a plurality oflazy-tong frame members, each of said members being pivotally mounted atits center to another frame member and pivotally connected at its endsto other members;

b. force generating means for generating a force to adjust the positionof said frames relative to each other;

c. means for connecting said force generating means to at least one ofsaid frames at a position intermediate the ends thereof;

d. connecting means for connecting said frames at said ends of saidmembers and comprising an angle iron corner member, said corner memberdisplacing the pivotally connected ends of the frame members of a framerelative to each other to thereby preclude said device from locking upin the collapsed position; and

. a plurality of stabilizer bars, each bar being pivotally mounted atits center to another stabilizer bar, and pivotally connected at itsends to respective ones of said angle iron corner members, and situatedsubstantially parallel to a lazy-tong frame member, said stabilizer barsand said angle iron corner members assisting in overcoming torsionalforces created when the position of said device is being adjusted.

1. An adjustably positionable structural device for use as a platformlift, scaffolding, extendible crane boom, structural member or the like,comprising: a. a plurality of frames, each of said frames comprising aplurality of lazy-tong frame members, each of said members beingpivotally mounted at its center to another frame member and pivotallyconnected at its ends to other members; b. force generating means forgenerating a force to adjust the position of said frames relative toeach other; c. means for connecting said force generating means to atleast one of said frames at a position intermediate the ends thereof;and d. a plurality of stabilizer bars, each bar being pivotally mountedat its center to another stabilizer bar, and pivotally connected at itsends to other stabilizer bars, and situated substantially parallel to alazy-tong frame member to assist in overcoming torsional forces createdwhen the position of said device is being adjusted.
 2. An adjustablypositionable structural device for use as a platform lift, scaffolding,extendible crane boom, structural member or the like, comprising: a. aplurality of frames, each of said frames comprising a plurality oflazy-tong frame members, each of said members being pivotally mounted atits center to another frame member and pivotally connected at its endsto other members; b. force generating means for generating a force toadjust the position of said frames relative to each other; c. means forconnecting said force generating means to at least one of said frames ata position intermediate the ends thereof; and d. said force generatingmeans including:
 2. a bridle mounted with respect to said piston;
 3. apulley mounted with respect to said bridle;
 3. An adjustablypositionable structural device for use as a platform lift, scaffolding,extendible crane boom, structural member or the like, comprising: a. aplurality of frames, each of said frames comprising a plurality oflazy-tong frame members, each of said members being pivotally mounted atits center to another frame member and pivotally connected at its endsto other members; b. force generating means for generating a force toadjust the position of said frames relative to each other; c. means forconnecting said force generating means to at least one of said frames ata position intermediate the ends thereof; d. connecting means forconnecting said frames at said ends of said members and comprising anangle iron corner member, said corner member displacing the pivotallyconnected ends of the frame members of a frame relative to each other tothereby preclude said device from locking up in the collapsed position;and e. a plurality of stabilizer bars, each bar being pivotally mountedat its center to another stabilizer bar, and pivotally connected at itsends to respective ones of said angle iron corner members, and situatedsubstantially parallel to a lazy-tong frame member, said stabilizer barsand said angle iron corner members assisting in overcoming torsionalforces created when the position of said device is being adjusted. 4.means for adjusting the position of said piston, thereby generating theforce required to adjust the position of said device; and
 5. a cableengaged with said pulley to impart to said frames the force beinggenerated by said piston, said frames being disposed exteriorly of saidforce generating means.